KR101758357B1 - Method and apparatus for retransmission - Google Patents

Abstract

A method for retransmitting a frame using a frame divided into a DL subframe and an UL subframe, the method comprising the steps of: receiving a data burst transmitted from a base station; Determining a feedback frame offset based on a relationship of a downlink subframe index to which a burst is transmitted, determining an index of a frame to transmit a feedback signal and an uplink subframe based on the frame offset, Transmitting the feedback signal from the index of the link sub-frame to the base station, and receiving a retransmitted data burst from the base station if a NACK message is included in the feedback signal.

Description

[0001] METHOD AND APPARATUS FOR RETRANSMISSION [0002]

The present invention relates to a retransmission method and apparatus.

A Hybrid Automatic Repeat reQuest (HARQ) scheme is a communication scheme that combines a Forward Error Correction (FEC) scheme and an Automatic Repeat Request (ARQ) scheme. The HARQ scheme can be classified into a synchronous HARQ scheme and an asynchronous HARQ scheme according to a transmission timing of a packet to be retransmitted. The synchronous HARQ scheme is a scheme for transmitting a retransmission packet for an initial transmission packet at a predetermined point in time and can be applied to an uplink HARQ retransmission. The asynchronous HARQ scheme can be applied to the retransmission of the downlink HARQ by the scheduler of the base station determining the transmission time point of the retransmission packet and transmitting the packet. In addition, the HARQ protocol can be divided into an adaptive HARQ scheme and a non-adaptive HARQ scheme according to the amount and location of resources to be allocated. The adaptive HARQ scheme is a scheme for transmitting while changing the amount and location of resources to be allocated. In the non-adaptive HARQ scheme, the amount and location of resources to be allocated are fixed and transmitted. The wireless communication system can achieve a high scheduling gain and a high-speed data transmission effect by appropriately combining the synchronous and non-HARQ methods with the adaptive and non-adaptive HARQ methods and using a small signaling overhead.

In a HARQ operation in which a base station (BS) transmits a data burst using a downlink (DL), a base station transmits control information including resource allocation information and a coded data burst HARQ And transmits the subpacket to the terminal. The control information may be inserted into a MAP by an information element (IE), and the MAP may be a DownLink Basic Assignment Advanced-MAP (DL B-A-A-MAP), for example. The terminal receiving the data burst decodes the data burst using the control information, determines the transmission time point of the feedback signal, and sends an ACK (positive acknowledgment) message or a NACK (negative acknowledgment) message to the base station.

In a HARQ operation in which a mobile station (MS) transmits a data burst using an uplink (UL), a mobile station receives control information including resource allocation information from a base station, and uses the received control information And encodes the data burst. The UE then transmits the HARQ subpacket, which is a coded data burst, to the base station at a predetermined transmission time. At this time, the control information may be inserted into the map, and the map may be, for example, an UpLink Basic Assignment Advanced-MAP (UL B-A-A-MAP). Then, the base station decodes the received data burst and sends an ACK message or a NACK message to the terminal as a feedback signal. If the UE receives the NACK message, the UE retransmits the data burst at the determined retransmission time.

In the HARQ operation, a transmission time interval (TTI) is used as a transmission time unit. A TTI is a duration in which an encoded packet in a radio air interface occupies a physical layer. The TTI is represented by an integer number of subframe units. For example, 1 TTI represents a time corresponding to one subframe. A data burst may be transmitted in at least one subframe, and in general, the number of subframes occupied by a data burst may be represented by a TTI. A TTI transmission or a default TTI transmission is referred to as a long TTI transmission when the data burst is transmitted in one subframe, and a long TTI transmission when the data burst is transmitted in successive subframes.

Thus, the BS and the UE determine a transmission time according to a predetermined transmission time determination method and perform a corresponding HARQ operation. Therefore, even if resources are available, the base station and the UE wait until a predetermined transmission time and perform a corresponding HARQ operation. Particularly, in a time division duplexing (TDD) mode in which a frame is partitioned into an uplink and a downlink subframe, a point at which data transmission is completed may be unnecessarily delayed according to a method of determining a transmission time point have.

A problem to be solved by the present invention is to provide a retransmission method for determining a transmission time point so as to complete a procedure related to data transmission at an early point in time.

A method for retransmitting using a frame divided into a DL subframe and an UL subframe in a terminal according to an embodiment of the present invention includes receiving a data burst transmitted from a base station, Determining a feedback frame offset according to a range in which a downlink subframe index of the data burst is transmitted in a range set based on the feedback frame offset, determining a time to transmit a feedback signal based on the feedback frame offset, Transmitting the feedback signal to the base station at a determined time, and receiving a retransmitted data burst from the base station if the feedback signal includes a NACK message.

Wherein the step of determining the feedback frame offset comprises the steps of: obtaining a reference time parameter calculated on the basis of the number of divided downlink subframes and the number of uplink subframes; A second range smaller than the sum of the uplink subframe number and the reference time parameter, a second range smaller than the sum of the uplink subframe parameter and the reference time parameter, Obtaining a range located in a third range smaller than the number of downlink subframes; determining the feedback frame offset to be 0 if the downlink subframe index on which the data burst is transmitted is located in the first range or the second range; And the data burst is transmitted Determining whether the feedback frame offset is 0 or 1 by comparing the value determined by the transmission information of the data burst with the time required for the data burst processing if the link subframe index is located in the third range; have.

로 결정되고, 상기 하향링크 서브프레임 수가 상기 상향링크 서브프레임 수보다 작으면

로 결정되며, D와 U는 각각 상기 하향링크 서브프레임 수와 상기 상향링크 서브프레임 수일 수 있다.If the number of downlink subframes is equal to or greater than the number of uplink subframes

, And if the number of downlink subframes is smaller than the number of uplink subframes

And D and U may be the number of the downlink subframe and the number of the uplink subframe, respectively.

The transmission information of the data burst may include a downlink subframe index on which the data burst is transmitted and a number of subframes occupied by the data burst.

로 결정되며, D는 상기 하향링크 서브프레임 수, U는 상기 상향링크 서브프레임 수, m'은 상기 데이터 버스트가 전송된 하향링크 서브프레임 인덱스 그리고 N_TTI는 상기 데이터 버스트가 점유하는 서브프레임 수일 수 있다.The value determined by the transmission information of the data burst is

D is the number of downlink subframes, U is the number of uplink subframes, m 'is a downlink subframe index to which the data burst is transmitted, and N _TTI is a number of subframes occupied by the data burst have.

Wherein when the feedback frame offset is 0, the feedback signal is transmitted in the same frame as the frame in which the data burst is transmitted, and if the feedback frame offset is 1, And determining a frame index to transmit the feedback signal in the frame.

Wherein the determining the transmission time point comprises: determining an uplink subframe index to transmit the feedback signal in any one of the uplink subframes included in the determined frame index if the feedback frame offset is 0, And determining the uplink subframe index to transmit the feedback signal in the first uplink subframe included in the determined frame index if the feedback frame offset is 1.

Determining the uplink subframe index when the feedback frame offset is 0, determining the uplink subframe index to be 0 if the downlink subframe index transmitted the data burst is in the first range, Determining a difference value between a downlink subframe index transmitted the data burst and a reference time parameter when the uplink subframe index is within the second range, May be determined as the last index of the uplink subframe.

A method of retransmitting a frame using a frame divided into a DL subframe and an UL subframe in a terminal according to another embodiment of the present invention includes receiving control information from a base station, Determining a packet transmission frame offset according to a range in which a downlink subframe index in which the control information is transmitted is located in a range, determining a time point at which a data burst is transmitted based on the packet transmission frame offset, Receiving a feedback signal for the transmitted data burst from the base station, and if the NACK message is included in the feedback signal, determining when to retransmit the data burst and retransmitting the data burst to the base station .

Wherein the determining the packet transmission frame offset comprises: obtaining a reference time parameter calculated based on the number of divided downlink subframes and the number of uplink subframes; determining a downlink subframe index to which the control information is transmitted A second range smaller than the sum of the uplink subframe number and the reference time parameter, a second range smaller than the sum of the uplink subframe parameter and the reference time parameter, Obtaining a range located in a third range smaller than the number of downlink subframes; if the downlink subframe index on which the control information is transmitted is located in the first range or the second range, the packet transmission frame offset is set to 0 Determining whether the control information is transmitted, When the probe frame index in the third range may include the step of determining the packet transmission frame offset to 0 or 1 based on a value determined by the time required for processing the data burst.

Wherein the transmission of the data burst includes transmitting the feedback signal in the same frame as the frame in which the control information is transmitted if the packet transmission frame offset is 0 and if the packet transmission frame offset is 1, Determining a frame index to transmit the data burst in a next frame, if the packet transmission frame offset is 0, transmitting the data burst in one of uplink subframes included in the determined frame index, Determining an uplink subframe index to transmit the data burst in a first uplink subframe included in the determined frame index when the packet transmission frame offset is 1, Decided In Im and the index of the uplink sub-frame may include the step of transmitting the data burst.

Determining the uplink subframe index if the packet transmission frame offset is 0, determining that the uplink subframe index is 0 if the downlink subframe index to which the control information is transmitted is located in the first range And determines the uplink subframe index as a difference value between the downlink subframe index to which the control information is transmitted and the reference time parameter when the first subframe is located in the second range, And determining an index as a last index of the uplink subframe.

Wherein the step of retransmitting to the base station comprises: determining an index of an uplink subframe that transmitted the data burst as an uplink subframe index to be retransmitted; transmitting the downlink subframe in which the control information is transmitted and the data burst Determining a frame index to be retransmitted by comparing a value determined by the uplink subframe index with a time required for the data burst processing, and retransmitting the data burst at the index of the determined frame and the uplink subframe . ≪ / RTI >

A method for retransmitting using a frame divided into a downlink subframe and an uplink subframe in a base station according to another embodiment of the present invention includes transmitting control information to a terminal, , Receiving a data burst transmitted according to the number of downlink subframes, calculating a reference time parameter calculated based on the number of divided downlink subframes and the number of uplink subframes, Determining an index of a downlink subframe to which a feedback signal is to be transmitted based on an uplink subframe index, determining a frame index to transmit the feedback signal based on a time point at which the data burst is separated by a feedback frame offset from the transmitted frame index ; Determining Transmitting the feedback signal from the index of the frame and the DL subframe to the UE and receiving the retransmitted data burst from the UE if the feedback signal includes the NACK message.

The step of determining the index of the downlink subframe may determine the index of the downlink subframe by a difference between the uplink subframe index on which the data burst is transmitted and the reference time parameter.

The feedback frame offset may be determined to be 0 or 1 by comparing a value determined by the downlink subframe that transmitted the control information and the uplink subframe index transmitted with the data burst with a time required for the data burst processing .

로 결정되며, U는 상기 상향링크 서브프레임 수, m'은 상기 데이터 버스트가 전송된 상향링크 서브프레임 인덱스, N_TTI는 상기 데이터 버스트가 점유하는 서브프레임 수 그리고 l'은 상기 제어 정보를 전송한 하향링크 서브프레임 인덱스일 수 있다.The value determined by the downlink subframe transmitting the control information and the uplink subframe index transmitted with the data burst is

Where U is the number of uplink subframes, m 'is an uplink subframe index to which the data burst is transmitted, N _TTI is the number of subframes occupied by the data burst, and l' And may be a downlink subframe index.

A retransmission apparatus of a terminal according to an embodiment of the present invention includes a receiver for receiving any one of control information from a base station, a first data burst and a feedback signal for a second data burst transmitted to the base station, A transmitter for transmitting a third data burst according to the information or for transmitting a feedback signal for the received first data burst or for retransmitting the second data burst according to the received feedback signal, And a transmission time determination unit for determining a transmission time point of the first data burst, a time point of transmitting a feedback signal to the first data burst, and a time point of retransmitting the second data burst, In the next frame of the transmitted frame, If the emitter or burst transmitting the feedback signal, and determines to transmit the third data burst, or the feedback signal from the first sub-frame that is included in the next frame.

The transmission time determination unit sets a range based on division information of a frame divided into a downlink subframe and an uplink subframe, and transmits the control information or the downlink subframe in which the first data burst is transmitted in the set range, A frame to be transmitted and an uplink subframe index to be transmitted can be determined by determining a feedback frame offset or a packet transmission frame offset according to the range in which the index is located.

According to the embodiment of the present invention, the order of the procedures related to data transmission can be sequentially transmitted without reversing.

1 is a flowchart schematically illustrating a downlink HARQ operation according to an embodiment of the present invention.
2 is a diagram illustrating a downlink HARQ transmission time point according to an embodiment of the present invention.
3 is a flowchart schematically illustrating an uplink HARQ operation according to an embodiment of the present invention.
4 is a diagram illustrating an uplink HARQ transmission time point according to an embodiment of the present invention.
5 is a flowchart schematically illustrating a downlink HARQ operation according to another embodiment of the present invention.
FIG. 6 and FIG. 7 illustrate a DL HARQ transmission time point according to another embodiment of the present invention.
8 is a flowchart schematically illustrating an uplink HARQ operation according to another embodiment of the present invention.
9 and 10 are views illustrating an uplink HARQ transmission time point according to another embodiment of the present invention.
11 is a schematic block diagram of a retransmission apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

In this specification, a terminal includes a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment , An access terminal (UE), an access terminal (AT), and the like, and may include all or some functions of a terminal, a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment,

In this specification, a base station (BS) includes an access point (AP), a radio access station (RAS), a node B, an evolved Node-B (eNB) A base station, a transceiver station (BTS), a mobile multihop relay (MMR) -BS, and the like, and may include all or some of functions of an access point, a radio access station, a Node B, an eNB, a base transceiver station, .

Hereinafter, a retransmission method according to an embodiment of the present invention will be described in detail with reference to an example of an HARQ scheme.

FIG. 1 is a flowchart schematically illustrating a downlink HARQ operation according to an embodiment of the present invention. FIG. 2 illustrates a downlink HARQ transmission time according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, the BS 100 transmits control information and a data burst (S110). At this time, the base station transmits the control information and the data burst using the downlink subframe (indicated by the subframe (m)) whose index is 'm' in the frame with the index 'i' . The frame index may be an index ranging from 0 to N-1 in the frame order when N frames are included in the super frame. The downlink and uplink subframe indexes may be sequentially indexed in the subframes allocated for the downlink and uplink in the frame.

The terminal 200 receiving the control information and the data burst determines the index (j, n) of the frame and the uplink subframe for transmitting the feedback signal (S120). The terminal 200 can obtain the index n of the uplink subframe to which the feedback signal is to be transmitted by Equation 1 and Equation 2, where K is a reference time parameter for determining a transmission time point (D) and the number of uplink sub-frames (U) constituting one frame as a reference timing parameter.

The ceil function in Equations (1) and (2) is a function that returns the nearest integer greater than or equal to the corresponding value, and the floor function is a function that returns the nearest integer less than or equal to the corresponding value. D is the number of downlink subframes and U is the number of uplink subframes. Then, the terminal 200 can obtain the index j of the frame to which the feedback signal is transmitted, using Equation 3 and Equation 4. Where z is the feedback frame offset used to determine the frame index for feedback transmission. If the feedback frame offset z is 0, a fast feedback procedure is performed in which a feedback signal is transmitted in the same frame as the frame i in which the data burst is transmitted. If the feedback frame offset z is 1, i + 1), a slow feedback procedure is performed in which a feedback signal is transmitted.

In Equation (3), the mod function is a function for performing a moduler operation, and N is the number of frames included in the superframe. N _TTI represents the number of subframes occupied by the data burst as a TTI (Transmission Time Interval) value, and T _proc is the time required for data burst processing, expressed in units of subframes.

The UE 200 transmits a feedback signal including an ACK message or a NACK message from the uplink subframe n of the frame j determined using Equations 1 to 4 to the base station 100 ). At this time, when the base station 200 receives the (200) NACK message, the base station 200 can retransmit the data burst.

Referring to FIG. 2, the HARQ operation of the TDD mode is performed using a frame in which a subframe included in one frame is divided into a certain number of downlink and uplink subframes, and one frame is divided into five downlink subframes (i.e., D = 5) and 3 UL subframes (i.e., U = 3) time is divided into, and the time required for the data burst handling (T _proc) is available for the three sub-frames (i.e., T _proc = 3 ). ≪ / RTI >

The base station 100 transmits the control information and the data burst in the downlink subframe 4 of the frame i to perform the first downlink HARQ operation. And transmits the feedback signal in the uplink subframe 2 of the frame (i + 1) determined using the uplink subframe 2. If the Node B 100 receives the NACK message, the Node B 100 may determine the retransmission time using the asynchronous HARQ scheme. For example, the Node B 100 may determine the retransmission time in the downlink subframe 3 of the frame (i + 2) Can be retransmitted.

Next, the base station 100 performs second and third downlink HARQ operations, which transmit control information and data bursts in the downlink subframe 1 and the downlink subframe 2 of the frame (i + 1), respectively The UE 200 transmits a feedback signal in the uplink subframe 0 of the frame i + 1 determined using Equations 1 to 4 for the second HARQ downlink operation, and the base station 100 ), The base station 100 can retransmit in the downlink subframe 1 of the frame (i + 2). Likewise, the third downlink HARQ operation is performed by occupying the uplink subframe 1 of the frame i + 1 and the downlink subframe 2 of the frame i + 2.

 In this case, the terminal 200 may transmit the feedback signal for the received data burst to the base station 100 later than the feedback signal for the received data burst. This is because the second and third downlink HARQ operations with a feedback frame offset z of 0 used in determining a frame index perform a fast feedback procedure while the first HARQ downlink operation with a feedback frame offset z = Occurs due to performing a late feedback procedure.

FIG. 3 is a flowchart schematically illustrating an uplink HARQ operation according to an embodiment of the present invention. FIG. 4 illustrates an uplink HARQ transmission time according to an embodiment of the present invention. Referring to FIG.

3, the base station 100 transmits control information in the downlink subframe l of the frame i (S310).

는 패킷 전송 프레임 오프셋(packet transmission frame offset)으로서 패킷 전송 프레임 오프셋(

)이 0이면 제어 정보를 전송한 프레임(i)과 같은 프레임에서 데이터 버스트가 전송되는 빠른 전송(fast transmission)이 수행되고, 패킷 전송 프레임 오프셋(v)이 1이면 다음 프레임(i+1)에서 데이터 버스트가 전송되는 늦은 전송(slow transmission)이 수행된다.The terminal 200 receiving the control information determines the index j and m of the frame and the uplink subframe at the transmission time of the data burst at step S320 and transmits the data burst to the base station 100 at step S330. The terminal 200 obtains the index (j, m) of the frame and the uplink subframe at the time of transmitting the data burst using Equations (5) to (7) and obtains the reference time parameter (K) as shown in Equation (2).

Is a packet transmission frame offset, which is a packet transmission frame offset (

) Is 0, a fast transmission in which the data burst is transmitted in the same frame as the frame (i) in which the control information is transmitted is performed. If the packet transmission frame offset (v) is 1, A slow transmission in which the data burst is transmitted is performed.

는 상향링크 HARQ 전송에서 사용하는 피드백 프레임 오프셋으로서 0 또는 1의 값을 가진다.The base station 100 receiving the next data burst determines a transmission time of a feedback signal including an ACK or NACK message in step S340 and transmits a feedback signal to the terminal 200 in step S350. The base station 100 determines the index k of the frame to which the feedback signal is to be transmitted using Equations 8 and 9 and determines that the downlink subframe index is equal to the index l of the subframe in which the control information is transmitted . At this time

Is a feedback frame offset used in uplink HARQ transmission and has a value of 0 or 1.

)은 수학식 7과 같이 구한다. 재전송할 상향링크 서브프레임 인덱스는 앞서 데이터 버스트 전송에 이용한 상향링크 서브프레임(m)과 같도록 결정된다.If the feedback signal received from the terminal 200 is a NACK message, the terminal 200 determines a retransmission time point (S360) and retransmits the data burst to the base station 100 (S370). The terminal 200 obtains the index p of the frame to be retransmitted using Equation (10), and transmits the packet transmission frame offset (

Is obtained as shown in Equation (7). The uplink subframe index to be retransmitted is determined to be the same as the uplink subframe m used for data burst transmission.

Referring to FIG. 4, in the first uplink HARQ operation performed by the base station 100 in the TDD mode by transmitting control information in the downlink subframe 4 of the frame i, 200 transmits the data burst in the uplink subframe 2 of frame (i + 1) determined using Equations (5) to (7). The base station 100 receiving the data burst occupies the downlink subframe 4 as the downlink subframe in which the control information has been previously transmitted in the frame (i + 2) determined using Equation (8) and Equation And transmits a feedback signal. The UE 200 receiving the NACK message repeats HARQ operation for retransmitting in the subframe 2, which is the same position as the uplink subframe in which the data burst is transmitted, of the frame (i + 3) determined using Equation (10) do.

When the base station 100 performs the second and third uplink HARQ operations in which control information is transmitted in the downlink subframe 1 and the downlink subframe 2 of the frame i + 1, 200 transmits a data burst in a UL subframe (0) of a frame (i + 1) determined using Equation (5) to Equation (7) for a second uplink HARQ operation, 100 transmits the feedback signal in the downlink subframe 1 of the frame i + 2 determined using Equations 8 and 9, and the terminal 200 receiving the NACK message transmits the feedback signal in the frame i + 2 ) In the uplink sub-frame (0). Similarly, the third uplink HARQ operation is performed in the uplink subframe 1 of the frame i + 1, the downlink subframe 2 of the frame i + 2, and the uplink subframe 2 of the frame i + 1).

)이 0인 두 번째와 세 번째의 상향링크 HARQ 동작은 빠른 전송을 수행하는 반면, 패킷 전송 프레임 오프셋(

)이 1인 첫 번째 HARQ 상향링크 동작은 늦은 전송을 수행하기 때문에 발생한다.When the HARQ operation is performed as described above, the UE 200 may transmit a data burst, which is allocated resources after the resource burst, to the BS 100 first. This is the packet transmission frame offset (< RTI ID = 0.0 >

) Of the second and third uplink HARQ operations perform fast transmission, while packet transmission frame offset (

) ≪ / RTI > is 1 occurs because the first HARQ uplink operation performs a late transmission.

Next, a method of determining a transmission time point at which a HARQ operation can be performed quickly will be described.

FIG. 5 is a flowchart schematically illustrating a downlink HARQ operation according to another embodiment of the present invention, and FIGS. 6 and 7 are views showing a downlink HARQ transmission time according to another embodiment of the present invention.

Referring to FIG. 5, the BS 100 transmits control information including resource allocation information and a data burst in a downlink sub-frame m 'of a frame i' (S510).

Upon receiving the control information and the data burst, the terminal 200 determines the index (j ', n') of the frame and the uplink subframe to which the feedback signal is to be transmitted based on the feedback frame offset z '(S520). The indexes (j ', n') of the frame and the UL subframe can be obtained as shown in Equations (11) to (13).

The UE 200 determines the number of downlink subframes D and the number of uplink subframes U by referring to the method of determining the indexes j 'and n' of the frame and the uplink subframe for transmitting the feedback signal, A reference time parameter K for determining a transmission time is obtained as shown in Equation (2). If the index m 'of the downlink sub-frame that transmitted the data burst is smaller than the reference time parameter K, the terminal 200 transmits the uplink sub-frame of the same frame as the frame i' 0 < / RTI > When the index m 'of the DL sub-frame that transmitted the data burst is equal to or greater than the reference time parameter K and smaller than the sum of the number of downlink sub-frames D and the number of uplink sub-frames U, (200) decides to transmit a feedback signal in the uplink sub-frame (m'-K) of the same frame as the frame (i ') which transmitted the data burst. If the index m 'of the DL sub-frame that transmitted the data burst is equal to or smaller than the sum of the reference time parameter K and the number of uplink sub-frames U and smaller than the number of downlink sub-frames D, The control unit 200 transmits the frame in the same frame as the frame (i ') that transmitted the data burst according to the feedback frame offset z' or transmits the frame in the frame (i '+ 1) which is the next frame. If the feedback frame offset z 'is 0, the UE 200 transmits in the uplink sub-frame U-1. If the feedback frame offset z' is 1, the UE 200 transmits the feedback signal in the uplink sub- .

The terminal 200 transmits a feedback signal at a transmission time determined in this manner (S530).

The downlink HARQ transmission time points using Equations (11) to (13) are summarized in Table 1.

division Subframe index Frame index Control information transmission

Data burst transmission

Feedback signal transmission

Referring to FIG. 5 and FIG. 6 together, the base station 100 transmits control information and a data burst in the downlink subframe 4 of the frame i (S510). At this time, as assumed above, the DL _TTI transmission in which the DL subframe and the UL subframe are divided at a ratio of 5 to 3 and the data burst is occupied by one subframe (i.e., N _TTI = 1) Assume a transmission with a time (T _proc ) 3 required for data burst processing.

The terminal 200 receiving the data burst transmitted from the base station 100 determines the transmission time using Equation 11 through Equation 13. Since the feedback frame offset z 'is 1, The feedback signal is transmitted in the UL subframe 0 (S530). If the base station 100 receives the NACK message, the base station 100 can arbitrarily determine the retransmission time. For example, when the base station 100 retransmits in the downlink subframe 1 of the frame (i + 1) S510), the UE 200 may transmit the feedback signal in the UL subframe 0 of the frame (i + 2) determined using Equations 11 to 13 (S530).

If the feedback frame offset z 'is 1, the UE 200 transmits a feedback signal for the data burst transmitted from the downlink subframe 4 to the uplink subframe 2 instead of the uplink subframe 2, 0), it is possible to transmit the feedback signal at a time point earlier by (U-1) subframe than the HARQ operation described with reference to FIG.

7, the UE 200 receives the downlink subframe 1 and the downlink subframe 2 of the frame (i + 1) from the base station 100 following the first downlink HARQ operation illustrated in FIG. And performs the second and third downlink HARQ operations by receiving the control information and the data burst, respectively. In this case, in the second and third downlink HARQ operations, even if the UE 200 performs a fast feedback procedure for transmitting a feedback signal using the same frame as the frame in which the data burst is transmitted, The feedback signal is not transmitted at a time before the HARQ operation.

FIG. 8 is a flowchart schematically illustrating an uplink HARQ operation according to another embodiment of the present invention. FIGS. 9 and 10 illustrate an uplink HARQ transmission time point according to another embodiment of the present invention. Referring to FIG.

Referring to FIG. 8, the base station 100 transmits control information including resource allocation information in a subframe (l ') of a frame (i') (S810).

')을 이용하여 데이터 버스트를 전송할 프레임 및 상향링크 서브프레임의 인덱스(j', m')를 결정한다(S820). 프레임 및 상향링크 서브프레임의 인덱스(j', m')는 수학식 14 내지 수학식 16과 같이 구할 수 있다. 이때

'는 패킷 전송 프레임 오프셋이다.The terminal 200 receiving the control information transmits the packet transmission frame offset (

') To determine the index (j', m ') of the frame to transmit the data burst and the uplink sub-frame (S820). The indexes (j ', m') of the frame and the uplink subframe can be found by Equations (14) to (16). At this time

'Is the packet transmission frame offset.

')에 따라 제어 정보를 전송한 프레임(i')과 같은 프레임에서 전송하거나 다음 프레임인 프레임(i'+1)에서 전송한다. 만약 패킷 전송 프레임 오프셋(

')이 0인 빠른 전송이면 단말(200)은 상향링크 서브프레임(U-1)에서 전송하지만 패킷 전송 프레임 오프셋(

')이 1인 늦은 전송이면 상향링크 서브프레임(0)에서 데이터 버스트를 전송하도록 결정한다.The terminal 200 determines the number of downlink subframes D and the number of uplink subframes U in order to determine the index (i ', m') of the frame and the uplink subframe for transmitting the data burst, A reference time parameter K for determining a transmission time is obtained as shown in Equation (2). If the index 1 'of the downlink subframe that transmitted the control information is smaller than the reference time parameter K, the terminal 200 transmits the uplink subframe of the same frame as the frame i' 0 < / RTI > When the index l 'of the DL subframe transmitting the control information is equal to or greater than the reference time parameter K and smaller than the sum of the DL subframe D and the UL subframe U, The base station 200 determines to transmit the data burst in the uplink sub-frame (1-K) of the same frame as the frame (i ') which transmitted the control information. When the index 1 'of the downlink subframe to which the control information is transmitted is equal to or smaller than the sum of the reference time parameter K and the uplink subframe number U and smaller than the downlink subframe number D, Lt; RTI ID = 0.0 > 200 < / RTI &

'In the same frame as the frame (i') in which the control information is transmitted or in the frame (i '+ 1) which is the next frame. If the packet transmission frame offset (

') Is 0, the UE 200 transmits in the uplink sub-frame U-1, but the packet transmission frame offset (

') Is 1, it is determined to transmit the data burst in the uplink sub-frame (0).

The terminal 200 transmits the data burst at the transmission time determined in this manner (S830).

'은 상향링크 HARQ 전송에서 사용하는 피드백 프레임 오프셋으로서 0 또는 1의 값을 가진다.The base station 100 receiving the next data burst determines a time point at which the feedback signal including the ACK or NACK message is transmitted using the reference time parameter K in operation S840. The base station 100 obtains the index k ', n' of the frame and the downlink subframe in which the feedback signal is to be transmitted, as shown in Equations (17) to (19). At this time

'Has a value of 0 or 1 as a feedback frame offset used in uplink HARQ transmission.

The base station 100 transmits a feedback signal at a transmission time determined in this manner (S850).

If the feedback signal received from the terminal 200 is a NACK message, the terminal 200 determines the retransmission time point (S860) and retransmits the data burst to the base station 100 (S870). The terminal 200 obtains an index p 'of a frame to be retransmitted using Equation 20 and Equation 21, and u is a packet retransmission frame offset u for determining an index of a retransmission frame. The uplink subframe index to be retransmitted is determined to be the same as the uplink subframe m used for data burst transmission.

The uplink HARQ transmission time using Equation (14) to Equation (21) is summarized in Table 2.

division Subframe index Frame index Control information transmission

Data burst transmission

Feedback signal transmission

re-send

Referring to FIGS. 8 and 9 together, the base station 100 transmits control information in the downlink subframe 4 of the frame i (S810). At this time, as assumed above, the DL _TTI transmission in which the DL subframe and the UL subframe are divided at a ratio of 5 to 3 and the data burst is occupied by one subframe (i.e., N _TTI = 1) Assume a transmission with a time (T _proc ) 3 required for data burst processing.

')이 1이므로 프레임(i+1)의 상향링크 서브프레임(0)에서 데이터 버스트를 전송한다(S830). 데이터 버스트를 수신한 기지국(100)은 수학식 17 내지 수학식 19를 이용하여 결정한 프레임(i+1)의 하향링크 서브프레임(1)에서 피드백 신호를 전송한다(S850).The terminal 200 receiving the control information transmitted by the base station 100 determines the transmission time point of the data burst using Equation (14) to Equation (16)

'Is 1, the data burst is transmitted in the uplink subframe 0 of the frame (i + 1) (S830). The base station 100 receiving the data burst transmits a feedback signal in the downlink subframe 1 of the frame (i + 1) determined using Equations (17) to (19) (S850).

If the UE 200 receives the NACK message, the UE 200 transmits the data burst at the position of the subframe (0) which transmitted the data burst earlier than the frame (i + 2) determined using Equation 20 and Equation (21) (S870).

10, the UE 200 receives the downlink subframe 1 and the downlink subframe 2 of the frame (i + 1) from the base station 100, following the first uplink HARQ operation described with reference to FIG. And performs the second and third uplink HARQ operations. First, for a second uplink HARQ operation, the UE 200 performs a fast transmission for transmitting a data burst in the UL subframe (0) of the frame (i + 1) determined using Equations (14) to . The base station 100 receiving the data burst transmits a feedback signal in the downlink subframe 1 of the frame (i + 2) determined using Equations (17) to (19). When the UE 200 receives the NACK message, it retransmits the data burst in the UL subframe (0) of the frame (i + 2) determined using Equation (20) and Equation (21). The next uplink HARQ operation is performed in the uplink subframe 1 of frame i + 1, the downlink subframe 2 of frame i + 2 and the uplink subframe 2 of frame i + 1).

In this manner, the terminal 200 receives the control information transmitted in the frame (i + 1) and receives the control information transmitted in the frame (i) even if it performs the fast transmission in which the data burst is transmitted in the frame (i + The data burst is not transmitted before the late transmission for transmitting the data burst in frame i + 1.

A retransmission apparatus for performing a retransmission method according to an embodiment of the present invention will be described with reference to FIG.

11 is a schematic block diagram of a retransmission apparatus according to an embodiment of the present invention.

11, the retransmission apparatus includes a reception unit 1100, a transmission time determination unit 1120, and a transmission unit 1130, and the retransmission apparatus may be formed in a terminal or a base station.

When a retransmission apparatus is formed in the UE, the reception unit 1110 receives the data burst from the base station, and the transmission time determination unit 1120 determines a frame index and an uplink subframe index to transmit the feedback signal, as described above. The transmitter 1130 transmits a feedback signal to the base station in the determined frame index and the uplink subframe index. Alternatively, the transmitting unit 1130 transmits the data burst to the base station, the receiving unit 1110 receives the feedback signal for the transmitted data burst from the base station, and when receiving the feedback signal including the NACK message, ) Determines the retransmission time point. The transmission unit 1130 retransmits the data burst to the base station at the determined retransmission time.

When the retransmission apparatus is formed in the base station, the reception unit 1110 receives the data burst from the terminal, and the transmission time determination unit 1120 determines the frame index and the downlink subframe index to transmit the feedback signal as described above. The transmitting unit 1130 transmits a feedback signal to the terminal in the determined frame index and the downlink subframe index. Alternatively, the transmitting unit 1130 transmits a data burst to the terminal, the receiving unit 1110 receives a feedback signal for the transmitted data burst from the terminal, and when receiving the feedback signal including the NACK message, the transmission time determining unit 1120 Determines the retransmission time point, and the transmission unit 1130 retransmits the data burst at the determined retransmission time point.

 While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (19)

delete A method for retransmitting a frame using a frame divided into a DL subframe and an UL subframe, the method comprising:
Receiving a data burst transmitted from a base station,
Determining a feedback frame offset according to a range where a downlink subframe index to which the data burst is transmitted is within a range set based on the division information of the frame,
Determining a time to transmit a feedback signal based on the feedback frame offset,
Transmitting the feedback signal to the base station at the determined time point, and
And receiving a retransmitted data burst from the base station if the feedback signal includes a NACK message,
The step of determining the feedback frame offset
Obtaining a reference time parameter calculated based on the number of divided downlink subframes and the number of uplink subframes;
A second range in which the downlink subframe index to which the data burst is transmitted is smaller than the reference time parameter, a second range in which the reference time parameter is larger than the sum of the uplink subframe number and the reference time parameter, Obtaining a range located in a third range smaller than the sum of the number of subframes and the reference time parameter and smaller than the number of downlink subframes;
Determining the feedback frame offset to be 0 if the downlink subframe index on which the data burst is transmitted is located in the first range or the second range; and
If the downlink subframe index on which the data burst is transmitted falls within the third range, a value determined by the transmission information of the data burst is compared with a time required for the data burst processing, and the feedback frame offset is set to 0 or 1 Determining step
/ RTI > 3. The method of claim 2,
If the number of downlink subframes is equal to or greater than the number of uplink subframes

, And if the number of downlink subframes is smaller than the number of uplink subframes

And D and U are the number of downlink subframes and the number of uplink subframes, respectively. 3. The method of claim 2,
The transmission information of the data burst is
Wherein the data burst includes a downlink subframe index on which the data burst is transmitted and a number of subframes occupied by the data burst. 5. The method of claim 4,
The value determined by the transmission information of the data burst is

, D is the number of downlink subframes, U is the number of uplink subframes, m 'is a downlink subframe index to which the data burst is transmitted, and N _TTI is a number of subframes occupied by the data burst Way. 3. The method of claim 2,
The step of determining the time to transmit
If the feedback frame offset is 0, transmits the feedback signal in the same frame as the frame in which the data burst is transmitted, and if the feedback frame offset is 1, transmits the feedback signal in the next frame of the frame in which the data burst is transmitted, And determining an index. The method of claim 6,
The step of determining the time to transmit
Determining an uplink subframe index to transmit the feedback signal in one of the uplink subframes included in the determined frame index if the feedback frame offset is 0,
Determining an uplink subframe index to transmit the feedback signal in a first uplink subframe included in the determined frame index if the feedback frame offset is 1
The retransmission method further comprising: 8. The method of claim 7,
The step of determining the uplink subframe index when the feedback frame offset is 0
Determines the uplink subframe index to be '0' if the downlink subframe index transmitted the data burst is in the first range, and determines the uplink subframe index to be ' Determining a difference value between the downlink subframe index and the reference time parameter as a difference between the uplink subframe index and the reference time parameter,
/ RTI > delete A method for retransmitting a frame using a frame divided into a DL subframe and an UL subframe,
Receiving control information from a base station,
Determining a packet transmission frame offset according to a range in which a downlink subframe index in which the control information is transmitted is located within a range set based on the division information of the frame,
Determining a time to transmit a data burst based on the packet transmission frame offset and transmitting the data burst to the base station;
Receiving a feedback signal for the transmitted data burst from the base station, and
If the NACK message is included in the feedback signal, determining a retransmission time point of the data burst and retransmitting the data burst to the base station
/ RTI >
Wherein determining the packet transmission frame offset comprises:
Obtaining a reference time parameter calculated based on the number of divided downlink subframes and the number of uplink subframes;
A first range in which the downlink subframe index to which the control information is transmitted is smaller than the reference time parameter, a second range in which the reference time parameter is larger than the sum of the uplink subframe number and the reference time parameter, Obtaining a range located in a third range smaller than the sum of the number of subframes and the reference time parameter and smaller than the number of downlink subframes;
Determining the packet transmission frame offset to be 0 if the downlink subframe index to which the control information is transmitted is located in the first range or the second range; and
Determining a packet transmission frame offset to be 0 or 1 based on a value determined by a time required for the data burst processing when a downlink subframe index to which the control information is transmitted is located in the third range
/ RTI > 11. The method of claim 10,
The step of transmitting the data burst
If the packet transmission frame offset is 0, transmits the data burst in the same frame as the frame in which the control information is transmitted, and if the packet transmission frame offset is 1, transmits the data burst in the next frame of the frame in which the control information is transmitted Determining a frame index to < RTI ID = 0.0 >
Determining an uplink subframe index to transmit the data burst in any one of uplink subframes included in the determined frame index if the packet transmission frame offset is 0,
Determining an uplink subframe index to transmit the data burst in a first uplink subframe included in the determined frame index if the packet transmission frame offset is 1,
Transmitting the data burst at an index of the determined frame and an uplink subframe
/ RTI > 12. The method of claim 11,
The step of determining the uplink subframe index when the packet transmission frame offset is 0
And determines the uplink subframe index to be 0 if the downlink subframe index to which the control information is transmitted is in the first range, and determines the uplink subframe index to be 0 if the downlink subframe index is located in the second range. Determining a difference value between the downlink subframe index and the reference time parameter as a difference between the uplink subframe index and the reference time parameter,
/ RTI > 12. The method of claim 11,
The step of retransmitting to the base station
Determining an index of an uplink subframe that transmitted the data burst as an uplink subframe index to be retransmitted,
Determining a retransmission frame index by comparing a value determined by a UL subframe transmitted with the control information and a UL subframe transmitted with the data burst with a time required for the data burst processing,
Retransmitting the data burst at the index of the determined frame and the uplink subframe
/ RTI > A method for retransmission using a frame divided into a downlink subframe and an uplink subframe in a base station,
Transmitting control information to the terminal,
Receiving a data burst transmitted according to the control information from the terminal,
Obtaining a reference time parameter calculated based on the number of divided downlink subframes and the number of uplink subframes;
Determining an index of a downlink subframe to which a feedback signal is to be transmitted based on the reference time parameter and an uplink subframe index to which the data burst is transmitted,
Determining a frame index to transmit the feedback signal based on a time point at which the data burst is separated by a feedback frame offset in a transmitted frame index;
Transmitting the feedback signal from the index of the determined frame and the downlink subframe to the terminal; and
If the NACK message is included in the feedback signal, receiving a data burst retransmitted from the UE
/ RTI > The method of claim 14,
The step of determining the index of the downlink sub-frame
And determining an index of the downlink subframe based on a difference between the uplink subframe index on which the data burst is transmitted and the reference time parameter. The method of claim 14,
Wherein the feedback frame offset is determined as 0 or 1 by comparing a value determined by a downlink subframe transmitting the control information and an uplink subframe index transmitted with the data burst with a time required for the data burst processing, Way. 17. The method of claim 16,
The value determined by the downlink subframe transmitting the control information and the uplink subframe index transmitted with the data burst is

Lt; / RTI >
U denotes the number of uplink subframes, m 'denotes an uplink subframe index to which the data burst is transmitted, N _TTI denotes a number of subframes occupied by the data burst, and l' denotes a number of downlink subframes The index is retransmitted. As a terminal retransmission apparatus,
A receiver for receiving any one of control information from a base station, a first data burst and a feedback signal for a second data burst transmitted to the base station,
A transmitter for transmitting a third data burst according to the control information to the base station or for transmitting a feedback signal for the received first data burst or for retransmitting the second data burst according to the received feedback signal,
A transmission time determiner configured to determine a transmission timing of the third data burst, a transmission timing of the feedback signal to the first data burst, and a transmission timing of the second data burst,
The transmission time determination unit
When the third data burst or the feedback signal is transmitted in the next frame of the frame in which the control information or the first data burst is transmitted, the third data burst or the feedback signal in the first subframe included in the next frame, A retransmission apparatus for determining to transmit a signal. The method of claim 18,
The transmission time determination unit
And sets a range based on division information of a frame divided into a downlink subframe and an uplink subframe, and sets a range in which the control information or the downlink subframe index in which the first data burst is transmitted is located in the set range And determining a frame to be transmitted and an uplink subframe index by determining a feedback frame offset or a packet transmission frame offset according to the determination result.

Images